Support conversion of clamped double values for pixel arrays in Crankshaft.

src/arm/lithium-arm.h

Index: src/arm/lithium-arm.h
diff --git a/src/arm/lithium-arm.h b/src/arm/lithium-arm.h
index f98c68f2197bb67e89f9aa5cb78e0be9a988d0c3..5a90f7a2ce4cdd5413e8238df9e13c8112c5b18e 100644
--- a/src/arm/lithium-arm.h
+++ b/src/arm/lithium-arm.h
@@ -73,6 +73,9 @@ class LCodeGen;
   V(CheckMap)                                   \
   V(CheckPrototypeMaps)                         \
   V(CheckSmi)                                   \
+  V(ClampDoubleToUint8)                         \
+  V(ClampIToUint8)                              \

[Kevin Millikin (Chromium), 2011/05/16 07:06:34]

It's strange that there is "Double", "I", and "Tagged" :)  I suggest "D", "I",
and "T" so the class names match the printed instruction names.

+  V(ClampTaggedToUint8)                         \
   V(ClassOfTest)                                \
   V(ClassOfTestAndBranch)                       \
   V(CmpID)                                      \
@@ -1927,6 +1930,44 @@ class LCheckNonSmi: public LTemplateInstruction<0, 1, 0> {
 };
 
 
+class LClampDoubleToUint8: public LTemplateInstruction<1, 1, 1> {
+ public:
+  explicit LClampDoubleToUint8(LOperand* value, LOperand* temp) {

[Kevin Millikin (Chromium), 2011/05/16 07:06:34]

No need for explicit here.

+    inputs_[0] = value;
+    temps_[0] = temp;
+  }
+
+  LOperand* unclamped() { return inputs_[0]; }
+
+  DECLARE_CONCRETE_INSTRUCTION(ClampDoubleToUint8, "clamp-d-to-uint8")
+};
+
+
+class LClampIToUint8: public LTemplateInstruction<1, 1, 0> {
+ public:
+  explicit LClampIToUint8(LOperand* value) {
+    inputs_[0] = value;
+  }
+
+  LOperand* unclamped() { return inputs_[0]; }
+
+  DECLARE_CONCRETE_INSTRUCTION(ClampIToUint8, "clamp-i-to-uint8")
+};
+
+
+class LClampTaggedToUint8: public LTemplateInstruction<1, 1, 1> {
+ public:
+  explicit LClampTaggedToUint8(LOperand* value, LOperand* temp) {
+    inputs_[0] = value;
+    temps_[0] = temp;
+  }
+
+  LOperand* unclamped() { return inputs_[0]; }
+
+  DECLARE_CONCRETE_INSTRUCTION(ClampTaggedToUint8, "clamp-t-to-uint8")
+};
+
+
 class LArrayLiteral: public LTemplateInstruction<1, 0, 0> {
  public:
   DECLARE_CONCRETE_INSTRUCTION(ArrayLiteral, "array-literal")